Any tiny leaks in the EPDM, that aren't enough to worry about during normal
rain will become immediately apparent. Plan on repairing the roof in
several places first. If the roof is even just a couple of years old, you
can bet you will find some leaks where it wasn't perfectly sealed together.
Another interesting idea is to figure out where all the losses are and see
about recovering them. I would guess that evaporation from the pool
accounts for a lot of that energy usage. Could a simple condenser in the
pool room's exhaust recover a lot of that latent heat somehow?